AMBER forcefield

Most of the calculations to be presented here employ the CVFF empirical force field. It contains cross-terms and an extensive parametrization for the first two rows of the periodic system and some selected heavier atoms. It should provide reliable geometries for all polymer systems investigated. To assess the impact of the force field on the final result, the widespread AMBER forcefield [34, 35] was also used, which has a simpler parametrization and does not contain cross-terms. AMBER is mostly used for molecular dynamics simulations and should provide somewhat poorer geometries. 

Chen, A. A., and Pappu, R. V. (2007a). Parameters of monovalent ions in the AMBER-99 forcefield Assessment of inaccuracies and proposed improvements. J. Phys. Chem. B 111, 11884-11887. 

MM methods provide a simpler representation of molecules, in which the fine detail of the electrons represented implicitly via partial charges and, is some cases, molecular polarisabilities. MM models represent molecules as a collection of atoms interacting through classical potentials. There are several MM models (or forcefields), and they dilfer in the functional forms of the interaction potential used between atoms, and in the means by which these interaction potentials are parameterized. Several good recent reviews of MM forcefields have been produced. Several MM forcefields have been developed for application to biomolecular systems. The most popular of these are the CHARMM, AMBER, ... 

PME in AMBER Sagui s group has contributed MG solvers to the PME forcefields. Available http //amber.scripps.edu/. 

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